Pre-positioning means for paper and ribbon inker in selective printing machines

ABSTRACT

A PRESSER DEVICE FOR MOVING A PAPER STRIP AND PRINTING RIBBON AT A CONTROLLED RATE OF SPEED AGAINST TYPE MEMBERS PRIOR TO STRIKING MOVEMENT OF PRINTING HAMMERS WHEREBY TO REDUCE PRINTING NOISE.

Sept. 20, 19'" (:L RY 3,605,612

FEE-POSITIONING MEANS FOR PAPER AND RIBBON INKER IN SELECTIVE PRINTINGMACHINES Filed April 21, 1969 2 Sheets-Sheet 1 Sept. 20, 1971 J. G.CLARY 5 PREPOSITIQNING MEANS FOR PAPER AND RIBBON INKER IN SELECTIVEPRINTING MACHINES Filed April 21. 1969 2 Sheets-Sheet 2 X MA/ UnitedStates Patent 3,605,612 Patented Sept. 20, 1971 3,605,612PRE-POSITIONING MEANS FOR PAPER AND RIBBON INKER IN SELECTIVE PRINTINGMACHINES John G. Clary, Pasadena, Calif., assignor to AddmasterCorporation, San Gabriel, Calif. Filed Apr. 21, 1969, Ser. No. 817,767Int. Cl. B41j 31/12; B41k l/40 US. Cl. 101-96 Claims ABSTRACT OF THEDISCLOSURE A presser device for moving a paper strip and printing ribbonat a controlled rate of speed against type members prior to strikingmovement of printing hammers whereby to reduce printing noise.

In certain types of data printing devices, such as used in printingcalculating machines and as exemplified by the machine disclosed andclaimed in the H. L. Clary et al. US. Pat. No. 3,151,546, issued onSept. 8, 1964, a paper strip forming a record medium is guided overdifferentially settable type members and over a printing ribbon locatedintermediate the type members and the paper strip. After the typemembers have been advanced to digitized positions, printing hammersimpact the paper strip and ribbon against the type characters so as totransmit a visible imprint from the type characters to the strip. Insuch cases, the ribbon must normally be spaced from the type members sothat it will not catch on the type characters as the type members areadvanced. Also, the paper must normally be spaced from the printingribbon so as to not rub against the same during advancement of thestrip. Otherwise, problems would be encountered in threading the tapethrough the printer and an ink-streaked appearance would be transferredto the tape.

Although printers of the above type operate satisfac torily, they createa considerable amount of noise during printing. I have discovered thatthis is due to a large extent to the diaphragm effect of the paper asthe hammers strike the same. That is, the paper normally forms arelatively large flexible surface which is spaced from the typecharacters and is therefore unsupported at the printing point. When thehammers strike the paper prior to impacting it against the typecharacters, the entire unsupported surface of the paper vibrates thesurrounding air, creating a loud sound. This extends to the free end ofthe paper which extends outside the machine.

Also, in printers of the above type, an appreciable amount of energy isabsorbed by the paper and ribbon as the spring-impelled hammers carrythe same into contact with the type characters. Thus, a relatively largeamount of energy must be initially imparted to the hammers to create avisible imprint and this further increases the generation of noise.Further, it has been found that a noticeable amount of smudging of theprinted type characters occurs, possibly due to minute relative shiftingbetween the paper and the printing ribbon during the printing impact ofthe hammers.

It therefore becomes a principal object of the present invention toreduce the printing noise in printers of the above type.

Another object is to reduce the force necessary to impel printinghammers against the paper record medium during the printing operation.

Another object is to reduce smudging of printed type characters inprinters of the above type.

The manner in which the above and other objects of the invention areaccomplished will be readily understood on reference to the followingspecification when read in conjunction with the accompanying drawings,wherein:

FIG. 1 is a sectional view through a printer of an adding machineembodying a preferred form of the present invention.

FIG. 2 is a front view of the printer and is taken sub stantially alongthe line 2-2 of FIG. 1.

FIG. 3 is an enlarged sectional plan view taken along line 33 of FIG. 1.

The illustrated embodiment of the present invention is disclosed inconnection with the commercially available Addmaster Adding Machine, andfor the sake of brevity, only those parts which comprise the printingdevice are disclosed herein. Reference may be had to the above notedClary et al. patent for a more complete disclosure of the addingmachine.

The printer comprises a plurality of rockable type sectors 11 arrangedside-by-side for independent movement about a common axis. Each sectorhas a series of type characters 12 spaced around the periphery thereofand ranging in value from Zero to 9. Means (not shown) are provided fordifferentially advancing the type sectors to position selected ones ofthe type characters at a printing line PL located directly below anelongated inking ribbon 13. The latter extends across all of the typesectors and is suitably advanced in an endwise direction during machineoperations.

The printer is supported by a pair of side frame plates 14 and 15 whichare held in spaced relation by certain structural members including apair of print hammer guide bars 16, 17, a hammer spring support plate18, and a pair of paper guide members 20 and 21. The latter members forma guide chute for guiding a paper tape 22 from a suitable supply roll(not shown) to a position over the printing line. Means (not shown)pushes the paper endwise in the chute as an incident to each machineoperation. The guide member 21 has rearwardly extending tabs, one ofwhich is shown at 23, for supporting a thin flexible shroud 24 having athickness on the order of .010 inch. The latter is attached to each tabat 25 and extends forwardly to form part of the paper guide chute.Openings 26 are formed in the shroud in alignment with the differenttype characters at the printing line. Since the paper is pushed endwise,the sides of the chute must be spaced apart sutliciently to permit freepassage of the paper therethrough.

The member 20 also has openings 27 formed therein in alignment withopenings 26. Such member is curved at 28 and extends upwardly tocooperate with a transparent guide member 30 to guide the paper upwardlyafter pass- 111g the printing line. The member 30 has a serrated tearolfedge 31, permitting the paper to be torn therealong.

Elongated printing hammers 32 are aligned with respective ones of thetype sectors 11 and are guided for endwise movment at the upper endthereof in openings formed in the guide bar 16. The lower ends of thehammers have openings 33 therein which are guided over the guide bar 17.The hammers have print heads 34 of relatively soft plastic materialsecured to the lower ends thereof.

The various print hammers are urged downwardly by respective springfingers 35 pivotally connected thereto at 39 and secured at 36 to themember 18. Normally, the hammers are held in their upper illustratedpositions by a three-lobed cam 37 which engages a follower bail 38pivotally supported at 40 and underlying the various Spring fingers.

According to the present invention, a pair of spaced presser members 41and 42 are provided. Since such members are similar, only one will bedescribed in detail.

The latter is slideably mounted between two adjacent print hammers 32and terminates at its lower end in a laterally extending flange 43 whichis guided along the forward edges of the two adjacent hammers and, inturn, terminates in two spaced presser feet 44 which extend through twoof the openings 27 in the member 20. The presser member is pivotallyconnected at 45 to a bail 46 fulcrumed at 47 and urged downwardly by atension spring 48. Normally, however, the bail 46 and presser membersare held in their illustrated upper positions by a three-lobed cam 50.

Both earns 37 and 50 are mounted on a printer control shaft 51 which isrotated one-third of a revolution in a clockwise direction during eachmachine operation.

It will be noted that the cam 50 has a relatively steep cam surface 52on each of its lobes and at approximately 210 degrees in each machinecycle, such surface passes below an edge 53 on bail 46 permitting thesprings 48 to lower the same and the presser members at a controlledrate of speed. In doing so, the presser feet 44 engage the paper 22 andpress the same down against the shroud 24 which flexes against theprinting ribbon 13 to move the same downwardly against the aligned typecharacter. This movement is slow enough to prevent generation of sounddue to movement of the paper. Thus, the ribbon is maintained in intimatecontact with the type character and the paper is maintainedsubstantially in contact with the ribbon. At this time, a radiallyextending shoulder 54 on one of the lobes of cam 37 passes under an edge55 of bail 38, permitting the spring fingers 35 to impel the printhammers 32 downwardly at an uncontrolled and high rate of speed toimpact the paper against the printing ribbon 13 and aligned typecharacter 12. Since the paper is held against the shroud 24 at thistime, no violent movement will be imparted along the paper to its freeend which would otherwise tend to generate a sound. Thereafter, thesucceeding lobes of the cams 37 and 50 raise the hammers and pressermembers to their illustrated positions whereby the ribbon 13 may riseabove the type characters 12 sufficiently to clear the same. Also, thepaper 22 is freed to be readily moved endwise along the paper chute.

I claim:

1. A printer for a calculating machine or the like comprising aplurality of type members each having a plurality of type charactersthereon,

means for differentially advancing said type characters to presentdifferent ones of said type characters to a printing line,

means for guiding a paper strip to said printing line and over said typemembers,

a thin flexible guide member intermediate said type members and saidstrip for normally maintaining said strip spaced from said type members,

printing impression means operable to strike said strip at said printingline whereby to transfer an imprint from said type characters at saidprinting line to said strip,

a presser device operable to press said strip against said guide memberand to press said guide member towards said type members adjacent saidprinting line, and

cyclically operable means including a control member for first causingoperation of said presser device and for thereafter causing operation ofsaid impression means while said presser device presses said stripagainst said guide member.

2. A printer according to claim 1 comprising means for supporting aprinting ribbon intermediate said type members and said guide member atsaid printing line and in spaced relation to said type characters,

said presser device being effective upon pressing said strip and saidguide member toward said type members to press said ribbon against saidtype characters at said printing line.

3. A printer for a calculating machine or the like comprising aplurality of type members each having a plurality of type charactersthereon,

means for differentially advancing said type members to presentdifferent ones of said type characters to a printing line,

means of guiding a paper strip to said printing line and over said typemembers,

a thin flexible guide member intermediate said type members and saidstrip for normally maintaining said strip spaced from said type members,

printing hammers aligned with respective ones of said type members andoperable to strike said strip whereby to transfer an imprint from saidtype characters at said printing line to said strip,

a printing ribbon intermediate said guide member and said type membersat said printing line,

means supporting said ribbon against said guide member and normallyspace from said type members,

presser device operable to press said strip toward said type memberswhereby to cause said guide member to press said ribbon against saidtype characters, and

cyclically operable means including a control member for first causingoperation of said presser device and for thereafter causing operation ofsaid hammers while said presser device is pressing said strip towardssaid type members.

4. A printer according to claim 3' wherein said last mentioned means iseffective to cause movement of said presser device at a controlled rateof speed.

5. A printer according to claim 4 comprising means on certain of saidhammers for guiding said presser device toward and away from said strip.

References Cited UNITED STATES PATENTS 2,427,418 9/ 1947 Rast 101-902,901,969 9/1959 Rabinow 101-93 3,001,470 9/1961 Nessel 101-96 3,031,9545/1962 Oldenburg et a1. 101-408X 3,139,169 6/ 1964 Wagemann l01-93X3,151,546 10/1964 Clary 101-93 3,218,965 11/1965 Simons et a1. 101-932,869,454 1/1959 Lang 101-93 WILLIAM B. PENN, Primary Examiner US. Cl.X.R.

